Rheological behaviour of 'Cérat Cosmétique, Ph. F.'

Synopsis Rheological analysis during the preparation of dermocosmetic products allows the deduction of properties related to consistency and fluidity, which are very important for cream application. This paper rheologically examines a cold-cream formula, 'Cérat Cosmétique' from the French Pharmacopoeia. 'Cérate', or cold-cream, is one of the most ancient cosmetic preparations. The Rheotest 2 viscometer, which was used for experimental determinations, allowed the rheograms to be plotted and the characteristic rheological constants to be calculated. On the basis of this information, the preparation under study was seen to present plastic behaviour. However, posterior thixotropic studies indicated that 'Cérat Cosmétique, Ph. F.' had no true thixotropic behaviour.